Collection, measurement and visualization of web data (traffic and usage data) for the purpose of analysis is termed as Web Analytics. Primarily related to website data, its scope can be extended to mobile and web based online applications as well.
Insights gleaned from Analytics can help businesses make informed decisions, measure performance and track/monitor operations. If implemented and consumed correctly it can serve as a trustworthy compass guiding you to the direction of the true north.
Sophisticated reporting and analytics accessible previously only to large companies that could afford them are now mainstream and easily obtainable, with many of them absolutely free!